diff --git a/solution/2900-2999/2976.Minimum Cost to Convert String I/README.md b/solution/2900-2999/2976.Minimum Cost to Convert String I/README.md
index 89e7133abb6a4..7809df863f835 100644
--- a/solution/2900-2999/2976.Minimum Cost to Convert String I/README.md	
+++ b/solution/2900-2999/2976.Minimum Cost to Convert String I/README.md	
@@ -53,8 +53,8 @@ tags:
 <strong>输入：</strong>source = "aaaa", target = "bbbb", original = ["a","c"], changed = ["c","b"], cost = [1,2]
 <strong>输出：</strong>12
 <strong>解释：</strong>要将字符 'a' 更改为 'b'：
-- 将字符 'a' 更改为 'c'，成本为 1 
-- 将字符 'c' 更改为 'b'，成本为 2 
+- 将字符 'a' 更改为 'c'，成本为 1
+- 将字符 'c' 更改为 'b'，成本为 2
 产生的总成本是 1 + 2 = 3。
 将所有 'a' 更改为 'b'，产生的总成本是 3 * 4 = 12 。
 </pre>
@@ -276,39 +276,84 @@ function minimumCost(
     changed: string[],
     cost: number[],
 ): number {
-    const g: number[][] = Array.from({ length: 26 }, () => Array(26).fill(Infinity));
-    for (let i = 0; i < 26; ++i) {
-        g[i][i] = 0;
-    }
-    for (let i = 0; i < original.length; ++i) {
-        let x: number = original[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        let y: number = changed[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        let z: number = cost[i];
+    const [n, m, MAX] = [source.length, original.length, Number.POSITIVE_INFINITY];
+    const g: number[][] = Array.from({ length: 26 }, () => Array(26).fill(MAX));
+    const getIndex = (ch: string) => ch.charCodeAt(0) - 'a'.charCodeAt(0);
+
+    for (let i = 0; i < 26; ++i) g[i][i] = 0;
+    for (let i = 0; i < m; ++i) {
+        const x = getIndex(original[i]);
+        const y = getIndex(changed[i]);
+        const z = cost[i];
         g[x][y] = Math.min(g[x][y], z);
     }
 
     for (let k = 0; k < 26; ++k) {
         for (let i = 0; i < 26; ++i) {
-            for (let j = 0; j < 26; ++j) {
-                g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+            for (let j = 0; g[i][k] < MAX && j < 26; j++) {
+                if (g[k][j] < MAX) {
+                    g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+                }
             }
         }
     }
 
-    let ans: number = 0;
-    let n: number = source.length;
+    let ans = 0;
     for (let i = 0; i < n; ++i) {
-        let x: number = source.charCodeAt(i) - 'a'.charCodeAt(0);
-        let y: number = target.charCodeAt(i) - 'a'.charCodeAt(0);
-        if (x !== y) {
-            if (g[x][y] >= Infinity) {
-                return -1;
+        const x = getIndex(source[i]);
+        const y = getIndex(target[i]);
+        if (x === y) continue;
+        if (g[x][y] === MAX) return -1;
+        ans += g[x][y];
+    }
+    return ans;
+}
+```
+
+#### JavaScript
+
+```js
+/**
+ * @param {string} source
+ * @param {string} target
+ * @param {character[]} original
+ * @param {character[]} changed
+ * @param {number[]} cost
+ * @return {number}
+ */
+var minimumCost = function (source, target, original, changed, cost) {
+    const [n, m, MAX] = [source.length, original.length, Number.POSITIVE_INFINITY];
+    const g = Array.from({ length: 26 }, () => Array(26).fill(MAX));
+    const getIndex = ch => ch.charCodeAt(0) - 'a'.charCodeAt(0);
+
+    for (let i = 0; i < 26; ++i) g[i][i] = 0;
+    for (let i = 0; i < m; ++i) {
+        const x = getIndex(original[i]);
+        const y = getIndex(changed[i]);
+        const z = cost[i];
+        g[x][y] = Math.min(g[x][y], z);
+    }
+
+    for (let k = 0; k < 26; ++k) {
+        for (let i = 0; i < 26; ++i) {
+            for (let j = 0; g[i][k] < MAX && j < 26; j++) {
+                if (g[k][j] < MAX) {
+                    g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+                }
             }
-            ans += g[x][y];
         }
     }
+
+    let ans = 0;
+    for (let i = 0; i < n; ++i) {
+        const x = getIndex(source[i]);
+        const y = getIndex(target[i]);
+        if (x === y) continue;
+        if (g[x][y] === MAX) return -1;
+        ans += g[x][y];
+    }
     return ans;
-}
+};
 ```
 
 <!-- tabs:end -->
diff --git a/solution/2900-2999/2976.Minimum Cost to Convert String I/README_EN.md b/solution/2900-2999/2976.Minimum Cost to Convert String I/README_EN.md
index 1575a16ef3d44..50fd6e6a57af3 100644
--- a/solution/2900-2999/2976.Minimum Cost to Convert String I/README_EN.md	
+++ b/solution/2900-2999/2976.Minimum Cost to Convert String I/README_EN.md	
@@ -268,39 +268,84 @@ function minimumCost(
     changed: string[],
     cost: number[],
 ): number {
-    const g: number[][] = Array.from({ length: 26 }, () => Array(26).fill(Infinity));
-    for (let i = 0; i < 26; ++i) {
-        g[i][i] = 0;
-    }
-    for (let i = 0; i < original.length; ++i) {
-        let x: number = original[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        let y: number = changed[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        let z: number = cost[i];
+    const [n, m, MAX] = [source.length, original.length, Number.POSITIVE_INFINITY];
+    const g: number[][] = Array.from({ length: 26 }, () => Array(26).fill(MAX));
+    const getIndex = (ch: string) => ch.charCodeAt(0) - 'a'.charCodeAt(0);
+
+    for (let i = 0; i < 26; ++i) g[i][i] = 0;
+    for (let i = 0; i < m; ++i) {
+        const x = getIndex(original[i]);
+        const y = getIndex(changed[i]);
+        const z = cost[i];
         g[x][y] = Math.min(g[x][y], z);
     }
 
     for (let k = 0; k < 26; ++k) {
         for (let i = 0; i < 26; ++i) {
-            for (let j = 0; j < 26; ++j) {
-                g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+            for (let j = 0; g[i][k] < MAX && j < 26; j++) {
+                if (g[k][j] < MAX) {
+                    g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+                }
             }
         }
     }
 
-    let ans: number = 0;
-    let n: number = source.length;
+    let ans = 0;
     for (let i = 0; i < n; ++i) {
-        let x: number = source.charCodeAt(i) - 'a'.charCodeAt(0);
-        let y: number = target.charCodeAt(i) - 'a'.charCodeAt(0);
-        if (x !== y) {
-            if (g[x][y] >= Infinity) {
-                return -1;
+        const x = getIndex(source[i]);
+        const y = getIndex(target[i]);
+        if (x === y) continue;
+        if (g[x][y] === MAX) return -1;
+        ans += g[x][y];
+    }
+    return ans;
+}
+```
+
+#### JavaScript
+
+```js
+/**
+ * @param {string} source
+ * @param {string} target
+ * @param {character[]} original
+ * @param {character[]} changed
+ * @param {number[]} cost
+ * @return {number}
+ */
+var minimumCost = function (source, target, original, changed, cost) {
+    const [n, m, MAX] = [source.length, original.length, Number.POSITIVE_INFINITY];
+    const g = Array.from({ length: 26 }, () => Array(26).fill(MAX));
+    const getIndex = ch => ch.charCodeAt(0) - 'a'.charCodeAt(0);
+
+    for (let i = 0; i < 26; ++i) g[i][i] = 0;
+    for (let i = 0; i < m; ++i) {
+        const x = getIndex(original[i]);
+        const y = getIndex(changed[i]);
+        const z = cost[i];
+        g[x][y] = Math.min(g[x][y], z);
+    }
+
+    for (let k = 0; k < 26; ++k) {
+        for (let i = 0; i < 26; ++i) {
+            for (let j = 0; g[i][k] < MAX && j < 26; j++) {
+                if (g[k][j] < MAX) {
+                    g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+                }
             }
-            ans += g[x][y];
         }
     }
+
+    let ans = 0;
+    for (let i = 0; i < n; ++i) {
+        const x = getIndex(source[i]);
+        const y = getIndex(target[i]);
+        if (x === y) continue;
+        if (g[x][y] === MAX) return -1;
+        ans += g[x][y];
+    }
     return ans;
-}
+};
 ```
 
 <!-- tabs:end -->
diff --git a/solution/2900-2999/2976.Minimum Cost to Convert String I/Solution.js b/solution/2900-2999/2976.Minimum Cost to Convert String I/Solution.js
new file mode 100644
index 0000000000000..3a41902b0cc09
--- /dev/null
+++ b/solution/2900-2999/2976.Minimum Cost to Convert String I/Solution.js	
@@ -0,0 +1,41 @@
+/**
+ * @param {string} source
+ * @param {string} target
+ * @param {character[]} original
+ * @param {character[]} changed
+ * @param {number[]} cost
+ * @return {number}
+ */
+var minimumCost = function (source, target, original, changed, cost) {
+    const [n, m, MAX] = [source.length, original.length, Number.POSITIVE_INFINITY];
+    const g = Array.from({ length: 26 }, () => Array(26).fill(MAX));
+    const getIndex = ch => ch.charCodeAt(0) - 'a'.charCodeAt(0);
+
+    for (let i = 0; i < 26; ++i) g[i][i] = 0;
+    for (let i = 0; i < m; ++i) {
+        const x = getIndex(original[i]);
+        const y = getIndex(changed[i]);
+        const z = cost[i];
+        g[x][y] = Math.min(g[x][y], z);
+    }
+
+    for (let k = 0; k < 26; ++k) {
+        for (let i = 0; i < 26; ++i) {
+            for (let j = 0; g[i][k] < MAX && j < 26; j++) {
+                if (g[k][j] < MAX) {
+                    g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+                }
+            }
+        }
+    }
+
+    let ans = 0;
+    for (let i = 0; i < n; ++i) {
+        const x = getIndex(source[i]);
+        const y = getIndex(target[i]);
+        if (x === y) continue;
+        if (g[x][y] === MAX) return -1;
+        ans += g[x][y];
+    }
+    return ans;
+};
diff --git a/solution/2900-2999/2976.Minimum Cost to Convert String I/Solution.ts b/solution/2900-2999/2976.Minimum Cost to Convert String I/Solution.ts
index f9ae974e8d2c9..80cd3006dc965 100644
--- a/solution/2900-2999/2976.Minimum Cost to Convert String I/Solution.ts	
+++ b/solution/2900-2999/2976.Minimum Cost to Convert String I/Solution.ts	
@@ -5,36 +5,35 @@ function minimumCost(
     changed: string[],
     cost: number[],
 ): number {
-    const g: number[][] = Array.from({ length: 26 }, () => Array(26).fill(Infinity));
-    for (let i = 0; i < 26; ++i) {
-        g[i][i] = 0;
-    }
-    for (let i = 0; i < original.length; ++i) {
-        let x: number = original[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        let y: number = changed[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        let z: number = cost[i];
+    const [n, m, MAX] = [source.length, original.length, Number.POSITIVE_INFINITY];
+    const g: number[][] = Array.from({ length: 26 }, () => Array(26).fill(MAX));
+    const getIndex = (ch: string) => ch.charCodeAt(0) - 'a'.charCodeAt(0);
+
+    for (let i = 0; i < 26; ++i) g[i][i] = 0;
+    for (let i = 0; i < m; ++i) {
+        const x = getIndex(original[i]);
+        const y = getIndex(changed[i]);
+        const z = cost[i];
         g[x][y] = Math.min(g[x][y], z);
     }
 
     for (let k = 0; k < 26; ++k) {
         for (let i = 0; i < 26; ++i) {
-            for (let j = 0; j < 26; ++j) {
-                g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+            for (let j = 0; g[i][k] < MAX && j < 26; j++) {
+                if (g[k][j] < MAX) {
+                    g[i][j] = Math.min(g[i][j], g[i][k] + g[k][j]);
+                }
             }
         }
     }
 
-    let ans: number = 0;
-    let n: number = source.length;
+    let ans = 0;
     for (let i = 0; i < n; ++i) {
-        let x: number = source.charCodeAt(i) - 'a'.charCodeAt(0);
-        let y: number = target.charCodeAt(i) - 'a'.charCodeAt(0);
-        if (x !== y) {
-            if (g[x][y] >= Infinity) {
-                return -1;
-            }
-            ans += g[x][y];
-        }
+        const x = getIndex(source[i]);
+        const y = getIndex(target[i]);
+        if (x === y) continue;
+        if (g[x][y] === MAX) return -1;
+        ans += g[x][y];
     }
     return ans;
 }